extract string from in R using regex

Question

I have this vector:

jvm<-c("test - PROD_DB_APP_185b@SERVER01" ,"uat - PROD_DB_APP_SYS[1]@SERVER2")

I need to extract text until "[" or if there is no "[", then until the "@" character.

result should be

PROD_DB_APP_185b
PROD_DB_APP_SYS

I've tried something like this:

str_match(jvm, ".*\\-([^\\.]*)([.*)|(@.*)")

not working, any ides?

@Sotos, sorry, your answer was right, one quick modification, between "-" and "[" or "@" — user1471980
– user1471980, Commented Jul 19, 2017 at 19:06
I have this vector - If this were a string you could match something, using (?<=-[ ])[^\[@]+(?=[\[@]) — user557597
– user557597, Commented Jul 19, 2017 at 19:15

Wiktor Stribiżew · Accepted Answer · 2017-07-19 19:28:41Z

A sub solution with base R:

jvm<-c("test - PROD_DB_APP_185b@SERVER01" ,"uat - PROD_DB_APP_SYS[1]@SERVER2")
sub("^.*?\\s+-\\s+([^@[]+).*", "\\1", jvm)

Details:

^ - start of string
.*? - any 0+ chars as few as possible
\\s+-\\s+ - a hyphen enclosed with 1 or more whitespaces
([^@[]+) - capturing group 1 matching any 1 or more chars other than @ and [
.* - any 0+ chars, up to the end of string.

Or a stringr solution with str_extract:

str_extract(jvm, "(?<=-\\s)[^@\\[]+")

Details:

(?<=-\\s) - a positive lookbehind that matches an empty string that is preceded with a - and a whitespace immediately to the left of the current location
[^@\\[]+ - 1 or more chars other than @ and [.

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